JP2009175168A - Application equipment and application method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide application equipment for achieving a color filer reducing irregularity generated in reflection light or the like at a low cost by satisfying requirements for specifications of chromaticity without unevenness on a large application region. <P>SOLUTION: The application equipment for jetting and applying an application material as minute droplets by discharge nozzles on an application object by an application head having a plurality of the discharge nozzles. The equipment uniformly applies the application material on the whole necessary application region of the application object by intermittently applying the material excluding certain pixels on the application region for one application with the application head, and complementing the intermittent application part and remaining application regions by once or more application head scanning operations, in a step of moving the application head relatively with respect to the object, supplying the material on the object, and applying the material on the region larger than the effective width of the application head. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating apparatus and a coating method for supplying a coating material to a coating object held at a predetermined position in the apparatus by a coating head having a plurality of discharge nozzles. In particular, a great effect can be expected when a coloring material is applied to the pixel in which the application area of the application object is divided into small sections (called pixels).

  Recent progress in image display technology of information terminals is remarkable, and display devices (displays) with very high definition are manufactured and put into practical use even for large screens or small screens. Under such circumstances, there is a strong demand for a display that enables high-quality image display at low cost. There is a color filter as a key device of a display that meets such demands, and various devices have been incorporated into the color filter manufacturing method and apparatus.

In the conventional technology for manufacturing methods and devices for such color filters,
Functions as a color filter by forming a light-shielding part in the form of a matrix with various materials that perform a light-shielding function on a glass substrate that is a base material, and filling the cells of the matrix-like light shielding part with a coloring material The coating method is used as the filling method.

  In this construction method, the steps of applying the coloring materials of RGB three colors are independent, and a shielding member (mask) that requires very high accuracy for light shielding is required in each step. Therefore, even in terms of man-hours (time) that requires a coloring process for each of the three colors, in addition to the coating used for the coloring of each of the three colors, an apparatus required for peeling off the extra colorant and used in those processes In terms of jigs and tools to be used, there was a problem that equipment and manufacturing costs were high.

  Recently, instead of a coating method, a coating device equipped with an inkjet head as a “coating head” for supplying a coating material is used to apply a “coating material” on a glass substrate or the like on which a light shielding portion is formed in a matrix as a base material. There has been proposed a method of manufacturing a color filter by supplying and applying a certain coloring material from an inkjet nozzle which is a “discharge nozzle” formed on an inkjet head (see Patent Document 1 and Patent Document 2).

JP 2002-273868 Japanese Patent No. 3925525

When a coloring material or the like is applied to a large area such as a color liquid crystal TV having a large screen, a plasma TV, or a color filter for a large display by using an inkjet head coating device, or like a display for a small information terminal Even when a small application area is required for each product, it is necessary to apply a coloring material or the like to a large area at a time when a plurality of pieces are produced on one substrate in parallel.
In such a case, in order to complete the application quickly and efficiently, an inkjet head having a large effective application width is prepared, the inkjet head and the substrate are relatively moved, and a coloring material is applied to the inkjet head during the movement. It is supplied and discharged and applied from an inkjet nozzle of an inkjet head to a place where a color filter, which is an application target, is to be applied.
Actually, there is a limitation on the arrangement density of the inkjet nozzles to which the coloring material is applied, and in order to realize a small arrangement density of the inkjet nozzles, and further, the arrangement of the inkjet heads to complement the unapplicable part between the adjacent inkjet heads Need to be in parallel.
However, this requires a large space in the moving direction even if the coating is performed linearly in a direction perpendicular to the moving direction of the coating apparatus.

As a method for solving this problem, Patent Document 1 discloses a method in which a plurality of inkjet heads are inclined and arranged to reduce the arrangement density of the inkjet nozzles to achieve the arrangement density of the inkjet nozzles necessary for coating. Has been.
When coating is performed by relatively moving the inkjet head and the substrate in this way, if there are some adverse effects due to the arrangement of the inkjet nozzles of the inkjet head, for example, variations in the coating amount due to uneven discharge of the coloring material for each inkjet nozzle. In a color filter manufactured by a coating apparatus equipped with the inkjet nozzle, a difference in transmitted light amount due to the variation appears linearly in the moving direction of the inkjet head.
When the manufactured color filter is incorporated in a display, a difference in the amount of light transmitted through the color filter becomes uneven color and is generated in a streak shape.

  In the development of the present application method and apparatus using an ink jet head, the present inventors made a simultaneous discharge operation with an ink jet nozzle formed at a fine pitch of several tens of μm in one ink jet head while working on this cause search. In this case, paying attention to the amount of the coloring material discharged from a certain inkjet nozzle, the amount is affected by the discharge of the adjacent inkjet nozzle, and the amount is 5 as compared with the case where the inkjet material is discharged alone. It was confirmed that the discharge amount of the coloring material increased by about 10%.

  Therefore, when adjacent ink jet nozzles are driven simultaneously, the discharge amount of several ink jet nozzles positioned at both ends of the ink jet head or the ink jet nozzles that simultaneously performed the painting operation is always smaller than other ink jet nozzles. . As a result, when continuous application is performed by linear movement of the inkjet bar, in either case, a portion with a small application amount appears in a stripe shape in the application region through which the inkjet nozzles at both ends have passed.

  In Patent Document 2, as a proposal for avoiding such an adverse effect, a pair of adjacent inkjet heads are shifted in the moving direction and arranged such that their ends overlap each other to form one long nozzle row, and another adjacent one. A pair of inkjet heads are shifted in a direction perpendicular to the moving direction, and the end portions thereof are also arranged so as to overlap each other to form one long nozzle row. ) It is disclosed that the occurrence of color unevenness can be suppressed by shifting the portions and not using the nozzles at the end portions with a small discharge amount.

  However, in the color filter manufacturing apparatus according to Patent Document 2, if the discharge of the nozzle at the end is stopped because the discharge amount is small, the discharge amount appears at the nozzle that becomes the end of the adjacent nozzle to be discharged. A portion applied by a nozzle having a reduced discharge amount continues in the moving direction of the ink jet head, and a difference in transmitted light amount occurs, resulting in color unevenness.

  If the inkjet heads are arranged and arranged in a direction perpendicular to the moving direction so as not to use the part with a low discharge amount, a large waste is generated in the arrangement space of the inkjet head, leading to an increase in the size of the apparatus. It is uneconomical to not use the nozzles on both ends of all inkjet heads on it.

In addition, as the inventors' investigation proceeds,
In the inkjet nozzles in one inkjet head, the total ejection amount of the coloring material per pixel is leveled by means such as combining ejection and non-ejection for each nozzle, and the difference in transmitted light amount and color unevenness As a result, it was confirmed that even if the color filter was sufficiently acceptable, subtle “swells” were generated on the pixel surface after drying due to the difference in drying time due to the time difference of the landing of the coloring material.
As a malfunction due to this, when the external light reflected light on the surface of the color filter is observed in a state where the brightness is low, the reflection of the light changes at this 'swell' portion, and if this 'swell' continues, it becomes a streak shape The part where reflection is strong or weak occurs.

  According to the present invention, the allowable value of chromaticity as a color filter is 3/1000 in the entire effective screen area, and the allowable value of variation in the coating amount of the coloring material that realizes the allowable value of chromaticity is 3% or less. It is confirmed that this is the target specification of the color filter, and the coating apparatus and method of the present invention satisfying the specification is realized. Further, the color filter is mounted on the display, and the surface is reflected by external light and reflected. The object is to realize a thing in which the intensity of reflected light does not partially occur even when there is light.

For this reason, in the present invention,
A coating apparatus and a coating method for spraying and coating a coating material as a small amount of droplets by a discharge nozzle on a coating target with a coating head having a plurality of discharge nozzles,
In the process in which the coating head moves relative to the coating object, supplies a coating material to the coating object, and coats a region of an effective width or more of the coating head.
Intermittent application in which a part of the pixels in the application area of one application by the application head is thinned out, and complementing the intermittent application part and the remaining application area by scanning the application head at least once or more,
It was set as the structure which apply | coats a coating material uniformly to the whole required application | coating area | region of the said application | coating target object.
The width of the intermittent application region is at least the width of the application region of the discharge nozzle with a low relative discharge amount located at both ends of all the discharge nozzles of the application head and / or at least 3 pixels or more.

  According to the present invention, the total amount per application area (pixel) of the coloring material that is the coating material that is discharged at once from the inkjet nozzle that is each “discharge nozzle” of the inkjet head that is the “application head” is uniformized, By mounting a plurality of inkjet heads and moving the inkjet head in the vertical and horizontal directions or applying a coloring material that is an application material, it is possible to apply a large area with less variation in the application amount, Furthermore, streaky coating unevenness that tends to occur in continuous areas due to linear movement of the inkjet head is prevented, and in addition, even if slight 'waviness' that occurs on the surface remains, it should be linearly continuous. Therefore, it is possible to realize a color filter in which the intensity of external light reflection does not partially occur during non-transparent light.

  Hereinafter, an embodiment of a coating apparatus of the present invention will be described in detail with reference to the accompanying drawings, taking a color filter manufacturing apparatus as an example.

FIG. 1 is a perspective view showing an embodiment of a coating apparatus for producing a color filter. The color filter manufacturing apparatus of this example supports a suction table 3, a coating gantry 4, a camera gantry 6 and the like on a machine base 1.
The suction table 3 that is a “holding stage” holds the glass substrate 2 by suction. In order to achieve positioning of the glass substrate 2, the suction table 3 is rotationally driven by a drive mechanism and a guide mechanism (not shown), and Y Driven in the direction.
The application gantry 4 is moved in the X direction on the machine base 1 by a drive mechanism and a guide mechanism (not shown), and the inkjet head bar 5 is controlled and driven in the X direction, so that the glass substrate 2 as the “application object” is “ The coloring material as “coating material” is discharged and applied from the inkjet nozzle 52 formed on the inkjet head 51 of the inkjet head bar 5 to the application area of the glass substrate 2 as “application target”.

  The inkjet head bar 5 is also held and driven in the Z direction and the Y direction by a drive mechanism and a guide mechanism (not shown) on the coating gantry, and is an optimum position for discharging and applying the coloring material from the inkjet nozzle 52 to the glass substrate 2. Moved to control.

Similarly to the coating gantry, the camera gantry 6 is reciprocated in the X direction on the machine base 1 by a drive mechanism and a guide mechanism (not shown).
The camera gantry 6 has alignment cameras 7 and 8 that are adjusted to the measurement reference position on the machine base 1 and mounted and fixed to the camera gantry 6. The alignment cameras 7 and 8 are attached to the glass substrate 2 by the alignment cameras 7 and 8. The mark (not shown) is read, the deviation from the reference point is measured, the inclination of the glass substrate 2 on the machine base 1 is calculated, the suction table 3 is rotated based on the calculation result, and / or in the Y direction. By moving, the alignment of the glass substrate 2 can be achieved.

  The camera gantry 6 is more preferably mounted and held with a scan camera 9 that detects and measures the colored material that has landed on the glass substrate 2, and this scan camera 9 is mounted on the camera gantry 6 with a drive mechanism (not shown). The guide mechanism reciprocates in the Y and Z directions.

  Here, X and Y represent directions orthogonal to each other set to define a plane parallel to the upper surface of the glass substrate 2 held by suction by the suction table 3, and Z is a plane defined by X and Y. The direction orthogonal to

  By adopting a two-dimensional CCD camera in place of the scan camera 9, the area of the droplets that have landed on the glass substrate is calculated from its diameter on the glass substrate surface, and the height is gradually increased in a constant step. It is possible to calculate the volume of the droplets by calculating each area and measuring the discharge amount of the coloring material from the inkjet nozzle 52 with high accuracy for each inkjet nozzle that has discharged the coloring material. It can be calculated.

FIG. 2 is a schematic diagram illustrating an example of the configuration of the inkjet head bar 5.
In this example, one row is constituted by five stages in which five ink jet heads 51 are arranged in parallel, and the ink jet head constituting the stage is divided into two stages, three stages and two stages, and six rows are arranged in a staggered manner. An example of a total of 30 heads is shown.

  The ink jet head bar 5 shown in FIG. 2 is for applying any of red (R), green (G), and blue (B) coloring materials. An inkjet head bar for applying the material is also provided.

FIG. 3 shows an arrangement pitch of the inkjet nozzles 52 provided in the inkjet head 51 in a direction perpendicular to the moving direction of the inkjet bar 5.
In order to realize the necessary arrangement density of the inkjet nozzles 52 by the two stages and the three stages of the inkjet heads 51 in a row, the inkjet nozzles 52 are arranged at an arrangement pitch P perpendicular to the moving direction of the inkjet heads 51. Is formed.
Furthermore, the inkjet nozzles 52 at the ends of the five inkjet heads 51 constituting the adjacent rows are arranged so as to have an arrangement pitch P, and the inkjet heads 51 are arranged according to the width to be applied by one movement of the inkjet bar 5. Place them consecutively.

FIG. 4 is a schematic block diagram illustrating an example of a configuration for controlling the inkjet head bar 5 and the inkjet head 51 in order to select the inkjet nozzle 52.
In this configuration, the scan camera 9 which is a measuring unit and the image data by the scan camera 9 (for example, image data corresponding to the state in which the coloring material is discharged and applied from all the inkjet nozzles 52 to the test region) are input. An image processing apparatus 11 that calculates the X, Y coordinates of the landing mark of the coloring material discharged from each inkjet nozzle 52 and the diameter, area, or volume of the coloring material;
A memory 12 which is a holding means for storing and holding necessary data such as a calculated diameter, area, or volume, and a discharge data table described later;
In order to select the inkjet nozzle 52 to be operated in consideration of the data such as the diameter, area, or volume held in the memory 12 and the data in the discharge data table, data and control signals with an external peripheral device are selected. And a control device 13 that is a control means for driving / stopping the inkjet head bar 5 including peripheral circuits, arithmetic circuits, and the like that handle input / output interfaces.

  Next, a mechanism for uniformly coating the coating area over the entire surface by the coating apparatus of the present invention will be described based on examples.

  As an embodiment of the present invention, a description will be given by applying and filling an appropriate amount of a coloring material into a pixel having a width of 180 μm and a length of 530 μm that can be used for a typical high-definition television receiver of 37 inch size.

  In this case, since the coloring materials of each of the three colors are applied to the pixels having the above-mentioned size with minute droplets, the density of the ink jet nozzle 52 needs to have a corresponding density. The ink jet inkjet nozzle 52 has an array density of 1800 dpi, and the amount of discharge of one coloring material (droplet) from one ink jet nozzle 52 is 30 pl (pico liter). A color filter is manufactured by ejecting and coating the square of the glass substrate 2 having a matrix-shaped light-shielding portion formed in 2 etc. = pixels.

  The arrangement pitch P of the 1800 dpi inkjet nozzles 52 is 14.11 μm. The narrow pitch value of 14.11 μm is based on the dimensions and mechanisms of the components constituting the inkjet nozzles 52 of the current basic inkjet system. It is difficult to realize with one inkjet head 51 due to restrictions. Therefore, this narrow pitch is realized by the five inkjet heads 51, that is, an inkjet head 51 is prepared in which the inkjet nozzles 52 formed on one inkjet head 51 have an arrangement interval of 360 dpi and 70.56 μm. The inkjet head 51 is realized with a configuration in which the pitch is shifted by 14.11 μm.

  The coloring material ejected and applied by the inkjet nozzle 52 rides on the matrix-shaped light-shielding portion formed on the substrate, and the coloring material between adjacent pixels is mixed, or the coloring material between the adjacent pixels is mixed to cause color mixing. It is necessary to avoid that. Therefore, in the measurement of the droplets discharged in advance from the inkjet nozzle 52, the average diameter of the droplets flying to the substrate is 40 μm, so that the coating is applied from the inkjet nozzle 52 to the substrate from both edges of a length of 530 μm. The area outside the position of 20 μm, which is the radius of the droplet during the flying of the colored material, is set as a discharge prohibited area, and the droplet of the colored material from the inkjet nozzle 52 in the range of 490 μm in the longitudinal direction and 140 μm in the short direction Fly and land.

The accuracy of the landing position in the short direction is possible by setting the speed of the coating gantry within a range that allows the productivity, but the restriction of the landing position in the longitudinal direction is limited by the inkjet nozzle 52 passing over the pixel. Of these, it is necessary to control ejection / application only to the inkjet nozzles 52 in the range to be landed.
Accordingly, the range to be ejected and applied from the inkjet nozzle 52 is that ejection and application of the coloring material to each pixel formed on the substrate is performed by the ejection and application control selected from the inkjet nozzle 52 positioned between 490 μm.

From the array pitch of 14.11 μm of the 1800 dpi inkjet nozzles 52, the number of inkjet nozzles 52 that can discharge and apply the coloring material to the length of 490 μm per pixel is 34.
As shown in FIG. 2, the arrangement pitch is realized by five inkjet heads 51 in the first to fifth arrangements in a row, and therefore the number of inkjet nozzles 52 that can be ejected and applied is the number of inkjet heads 51 at the end. The six ink jet nozzles and the remaining four ink jet heads 51 to seven ink jet nozzles 52 can be discharged and applied.

  That is, in the row of five inkjet heads 51, one of the six inkjet nozzles 52 should be ejected and applied to the corresponding pixel, and the other inkjet heads 51 should be ejected and applied by the seven inkjet nozzles 52. As a kimono, the ejection and non-ejection of 34 target inkjet nozzles 52 are controlled by the control means.

  As a method for stabilizing the discharge amount by the discharge / application to the pixels of the 34 inkjet nozzles 52 to be the object, the present inventor controls the discharge / non-discharge of every other inkjet nozzle 52 to perform the discharge operation. It has been confirmed that the method of discharging the coloring material from the inkjet nozzle 52 that has been instructed to discharge is effective. Therefore, by controlling so that the adjacent inkjet nozzles 52 in one inkjet head 51 do not discharge simultaneously from the 34 inkjet nozzles 52 described above, a stable amount of coloring material can be applied to each pixel by the inkjet nozzles 52. Can be discharged and applied.

If every other discharge control is performed, the discharge amount from the ink jet nozzle 52 is reduced, but the respective discharge amounts are constant and equal, and the application amount of the coloring material to the pixels is stable and the allowable value of the application amount Application within 3% becomes possible.
In this case, every other inkjet nozzle 52 can be operated, as described above, in a row of five inkjet heads 51, one being six inkjet nozzles 52 ejecting and applying to the corresponding pixels. Since the other inkjet heads 51 are the seven inkjet nozzles 52, the inkjet heads 51 that are targeted by the six inkjet nozzles 51 are three or seven inkjet nozzles 52 that are targeted. From 51, the following combinations using 4 or 3 can be selected.
1) Total 17 of 3 + 4 + 3 + 4 + 3 2) Total of 17 of 3 + 3 + 4 + 3 + 4 In order to discharge and apply 1500 pl of coloring material to one pixel using these 17 inkjet nozzles 52, 3 color materials from each inkjet nozzle 52 Thus, a total of 51 coloring materials can be discharged, and the discharge and application of 50 coloring materials necessary for applying one pixel can be secured.
That is, when the discharge of the remaining one coloring material is not discharged in normal times and the discharge amount of each inkjet nozzle 52 is slightly reduced, the discharge from the inkjet nozzle 52 for this margin can be performed appropriately. A coating amount can be secured.

  30 pl which is the discharge amount of the coloring material from the individual inkjet nozzles 52 is the latest state before the start of coating by measurement by test firing of each equipped inkjet head 51 performed in advance or by test pattern inspection described later. The exact one-time discharge amount such as the diameter and volume of the landing mark in the test pattern application is confirmed and adjusted, the data is stored in the memory as the discharge data table, and the stored numerical values and the like of the ink jet nozzle 52 are used. The selection and ejection / non-ejection control are performed, and the chromaticity tolerance value as a color filter is 3/1000 over the entire effective screen area, and the coating material variation tolerance value that realizes this chromaticity tolerance value is Satisfies chromaticity specification of 3% or less.

In this way, 1500 pl coloring material is stably ejected and applied to one pixel, the total ejection amount of the coloring material per pixel is leveled, and a color filter that can sufficiently tolerate the difference in transmitted light amount and color unevenness Even so, it was confirmed that subtle “swells” occurred on the pixel surface after drying due to the difference in drying time due to the time difference of the landing of the coloring material.
As a malfunction due to this, when the external light reflected light on the surface of the color filter is observed in a state where the brightness is low, the reflection of the light changes at this 'swell' portion, and if this 'swell' continues, it becomes a streak shape The part where reflection is strong or weak occurs.

  Therefore, in the present invention, the discharge / non-discharge instructions from the control device to the inkjet bar 5, the inkjet head 51, and the inkjet nozzle 52 are shown at both ends of the width of one inkjet head bar 5, as shown in FIG. Intermittent application is performed by partially thinning out the number of non-ejection pixels from the end of the ejection region, and the non-ejection portion is complemented by reciprocating scanning of the inkjet head bar 5 at least one reciprocation to complete the application.

  In this case, the number of pixels included in the region of the intermittent portion is at least the number of pixels in the width of the application region of the discharge nozzle having a low relative discharge amount in adjacent simultaneous discharge located at both ends of all the discharge nozzles of the application head, and / Or preferably at least 3 pixels or more.

  A plurality of ink-jet heads 51 having a configuration in which an array density of 1800 dpi is arranged as a group of five ink-jet heads 51 are prepared, and ink-jet nozzles 52 adjacent to each other are arranged with an arrangement pitch P as shown in FIG. By mounting and deploying on the head bar 5, it is possible to configure the inkjet bar 5 having a necessary coating width in a region to be coated at once, and the required process time, etc., for a request for coating a large coating area Thus, it is possible to design the inkjet head bar 5 to be used.

The inkjet nozzle 52 shown here represents one of the coloring materials to be applied, and it is necessary to prepare for each color of RGB as a color filter.
In this case, it is preferable that the numbers to be thinned out in adjacent pixels of the RGB color materials are set differently.
As a result, the total discharge amount of the coloring material to the pixel is leveled to a predetermined amount, and even if a slight swell occurs on the surface after the coloring material is discharged to the pixel and dried, the angle is within the visible range. By confirming the reflection of outside light, it can be prevented that there is a light and dark streak.

  As described above, by providing the memory 12 as the measuring means and the holding means, the memory 12 holds each time the application operation by the ink jet nozzle 52 formed on the ink jet head 51 mounted on the ink jet head bar 5 is performed. Since the diameter, area, or volume of the landing mark due to the discharge / application of each inkjet nozzle is updated, when the next application operation by the inkjet head bar 5 is performed, the latest application amount of each inkjet nozzle 52 is determined. According to the data, the inkjet head bar 5 is controlled, and the inkjet nozzle 52 to be ejected is selected in accordance with the position coordinates of the pixel in the application region, and the “ejection” control command is issued to determine the optimum application amount of the coloring material. Can be maintained.

  Note that the control device 13 receives data from the respective ink-jet nozzles 52 held in the memory 12 such as data such as the volume of the landing marks measured by discharging the coloring material from the respective ink-jet nozzles 52 and data in the discharge data table. According to the discharge amount data, the supply amount of the coloring material is determined by selecting the inkjet nozzle 52 to be discharged and the number of discharges of the droplets of the coloring material so that the supply amount of the coloring material to be landed on each pixel region 23 is constant. It is preferable to control the corresponding inkjet head 51 and inkjet head bar 5 in order to average over the entire coating area, and as a result, it is possible to satisfy the demand for chromaticity as a color filter with high accuracy.

  Alternatively, the discharge amount from each inkjet nozzle 52 held in the memory 12 such as data such as the volume obtained by measuring the landing mark from which the coloring material was discharged from each inkjet nozzle 52 or the data in the discharge data table. Based on the data, the selection of the corresponding inkjet nozzle 52 to be ejected and the control of the ejection amount of the droplet from the inkjet nozzle 52 are performed with the aim of optimizing the supply amount of the coloring material to be landed on each pixel region 23. In order to keep the supply amount of the coloring material within the allowable error range, it is preferable to control the corresponding ink jet head 51 and the ink jet head bar 5 so that the application amount of the entire application region is within the allowable range. Can meet the demands of chromaticity with higher accuracy

  When the supply amount is averaged over the entire application region by selecting the ink jet nozzle and controlling the number of discharges, the coating quality of the coloring material for the pixel region 23 can be remarkably improved, and the individual discharge amount of the ink jet nozzle 52 can be controlled. In the latter case, the ink jet nozzle 52 in which the discharge amount per time with respect to the pixel region 23 is increased or decreased can be used for the coating operation, and the ink jet nozzle 52 that can maintain the coating quality of the coloring material and can be used. The increase in the number can be made compatible.

Next, the operation of the color filter manufacturing apparatus having the above configuration will be described.
FIG. 6 is an example of a timing chart for explaining the processing of the coloring material application and the test pattern inspection. In this example, the coloring material is applied to the object to be applied by two reciprocating movements of the coating gantry 5, and the coating process is performed with a test pattern inspection process being inserted between the first and second reciprocating movements. I am trying to finish.

  FIG. 7 shows a sample in which six color filters CF are formed on the glass substrate 2, and a test pattern TP for each coloring material is formed in a surplus area outside the color filter CF. ing.

  FIG. 8 is an enlarged view of the test pattern TP forming portion, and the test pattern TP formed by the ink jet nozzles 52 for three colors is assumed to be inspected by the scan camera 9 or the like mounted on the camera gantry 6. Show. This test pattern TP is the shape itself in which the coloring material discharged from each inkjet nozzle 52 has landed on the glass substrate 2 on the glass substrate 2, and performs image processing for imaging by the scan camera 9 or the two-dimensional CCD camera.

  As shown in FIG. 8, the coloring materials are separated from each other and landed in a staggered manner. By doing so, the interval between the coloring materials is large, the image processing at the time of measurement is free, the inspection accuracy is improved, and the test pattern TP is generated by the scan camera 9 or the two-dimensional CCD camera mounted on the camera gantry 6. The volume can also be measured and calculated by changing the measurement height in the diameter, area, or Z direction of the ink landing mark along with the X and Y coordinates of the ink landing mark and continuously calculating the area. . Then, when an improper ink landing mark shape or ejection failure such as non-landing is detected, necessary countermeasures (color filter production interruption, ink jet head 51 replacement, etc.) are immediately taken as described later. It is possible to minimize the production of defective products.

  FIG. 9 is a flowchart for explaining an example of the test pattern inspection process. Note that the timing chart of FIG. 8 does not show processing based on the flowchart of FIG.

The test pattern inspection process will be described with reference to FIG.
In step SP1, after the test glass substrate is carried into the suction table 3 by a carry-in robot (not shown) or the like, in step SP2, rough positioning of the test glass substrate is achieved by external shape regulating means (not shown). In step SP3, the test glass substrate is sucked by the suction table 3. Thereafter, in step SP4, the camera gantry 6 is moved forward. In step SP5, the alignment mark of the test glass substrate is detected, and the Y direction is detected. Positioning and alignment in the direction of θ (rotation around the Z axis) are achieved, and in step SP6, the camera gantry 6 is moved backward.

  Next, in step SP7, the coating gantry 4 is moved forward / backward, and the X coordinate value of the coating gantry 4 is output. In step SP8, the coating gantry 4 reaches the test pattern coating position based on the X coordinate value. If the test pattern application position has not been reached, the process of step SP7 is performed again.

  If it is determined in step SP8 that the application gantry 4 has reached the test pattern application position, the movement of the application gantry 4 is stopped in step SP9, and the liquid of the coloring material is discharged from all the inkjet nozzles 52 of the inkjet head bar 5. In step SP10, the application gantry 4 is moved back and stopped at the standby position.

Next, a flow for imaging and inspecting the test pattern (TP) is entered. Here, in step SP11, the camera gantry 6 is moved forward, and in step SP12, it is determined whether or not the camera gantry 6 has reached the test pattern inspection position. judge.
If the test pattern inspection position has not been reached, step SP11 is performed again.

  If it is determined in step SP12 that the camera gantry 6 has reached the test pattern inspection position, the camera gantry 6 is stopped in step SP13, and the scan camera 9 is moved in the Y direction in step SP14 to perform the test. The test pattern is imaged to the end while detecting the pattern, and then the scan camera 9 is returned to the standby position in the Y direction.

  After the processing of step SP14, in step SP15, the camera gantry 6 is moved back and stopped at the standby position to finish the “test pattern (TP) imaging flow”, and in step SP16, the suction of the test glass substrate is released. , Discharge and finish the series of processing.

  In parallel with the processing in step SP15 and step SP16, in step SP17, the detection signal from the scan camera 9 is image-processed, and the X, Y coordinates and the diameter, area and / or volume of the landing mark of the coloring material are measured. In step SP18, the coordinate position information detected from the colored material landing mark of the test pattern is input, and in step SP19, the position information (coordinate values) of all the pixels on the test glass substrate is input. In SP20, other parameters are input. In step SP21, the selection of inkjet nozzles to be ejected corresponding to all pixels and the calculation / creation of the ejection data table with the ejection amount (number of ejections) as basic data are performed. In step SP22, the calculation result is stored in the ejection data table, and image processing and measurement are performed. And it ends the series of processing such as calculation.

Next, an example of the color filter manufacturing process will be described with reference to the color filter manufacturing flowchart shown in FIG.
In order to realize efficient operation of the apparatus, the application gantry 4 is moved back and forth at least once with respect to the required application region so that the application operation is completed by “one stroke writing” from a predetermined start position of the application gantry 4. It is desirable to set the width of the effective inkjet head nozzle so that it is sufficient.

  In step SP1 in FIG. 10, after the glass substrate 2 is carried into the suction table 3 by a carrying robot (not shown) or the like, the rough positioning of the glass substrate 2 is achieved by the outer shape regulating means (not shown) in step SP2. To do. In step SP3, the glass substrate 2 is sucked by the suction table 3, and then in step SP4, the camera gantry 6 is moved forward. In step SP5, the alignment mark of the glass substrate 2 is detected, and the Y direction, θ ( The alignment of the glass substrate 2 is achieved by positioning in the theta direction, and the camera gantry 6 is moved back in step SP6.

  In step SP7, it is determined whether the application is the forward pass application or the return pass application.

  If it is determined in step SP7 that the forward application is performed, in step SP8, the application gantry 4 is moved forward, and the X coordinate value of the application gantry 4 is output. If determined, in step SP9, the application gantry 4 is moved backward to output the X coordinate value.

  When the process at step SP8 or the process at step SP9 is performed, it is determined at step SP10 whether or not the application has been performed up to the end of the application region.

  If it is determined in step SP10 that the application has not been performed until the end of the application region, in step SP11, the X coordinate output signal of the application gantry 4 and the discharge data table are compared, and in step SP12, the X coordinate is It is determined whether or not the discharge data matches. If the X coordinate and the discharge data match, in step SP13, a droplet of the coloring material is discharged by the inkjet nozzle 52. The process returns to step SP7.

The color material droplet discharge operation in step SP13 will be described.
As shown in FIG. 5A, a few pixels from the end of the application region where a small amount of application tends to appear in the application region where the inkjet nozzles at both ends have passed through the application of one scan (outward path) of the inkjet head bar 5. The non-ejection range is non-ejection and intermittent application is performed leaving unapplied pixels. As shown in FIG. 5B, in one scan of the return path, the area is overlapped and the inkjet head bar 5 is shifted in the Y direction to move the portion. Control to apply the coloring material to the remaining area including the supplementary discharge.

  For slight variations in the discharge amount of the individual coloring materials from the inkjet nozzles 52, data such as the volume measured by the control device 13 for the landing marks from which the coloring materials were discharged from the inkjet nozzles 52, and the like in the discharge data table The combination of the inkjet nozzles 52 to be ejected so that the supply amount of the coloring material to be landed on each pixel area 23 is made constant by the ejection amount data from the respective inkjet nozzles 52 held in the memory 12 such as data. By controlling the corresponding inkjet head 51 and inkjet head bar 5 so as to average the supply amount of the coloring material over the entire coating region by selection, the ejection operation is controlled so as to satisfy the requirement for the allowable amount of ejection as a color filter. I do.

  Alternatively, each inkjet nozzle held in the memory 12 such as data such as a volume obtained by measuring the landing mark from which the coloring material is ejected from each inkjet nozzle 52 by the control device 13 or data in the ejection data table. In order to optimize the supply amount of the coloring material to be landed on each pixel area 23 based on the discharge amount data from 52, the combination of the corresponding inkjet nozzles 52 to be discharged and the coloring material from the inkjet nozzles 52 are selected. In order to keep the supply amount of the coloring material within the allowable error range by adjusting the increase / decrease of the discharge amount of the ink and the discharge command of the number of droplets, the corresponding inkjet head 51 and inkjet head bar 5 are controlled to It is preferable that the coating amount is within an allowable range, and as a result, a color filter is obtained. Of controlling the ejection operation of the liquid droplet of the coloring material to meet the requirements of the chromaticity.

  Subsequently, in step SP10, it is determined whether application has been performed to the end based on the X coordinate value.

  If it is determined in step SP12 that the X coordinate does not match the ejection data, or if the process in step SP13 is performed, the process returns to step SP7 to determine the return path.

  If it is determined in step SP10 that the application has been performed up to the end, it is determined in step SP14 whether or not the application is the first time in the forward path. If the application is the first time in the forward path, the application is performed in step SP15. The gantry 4 is moved to the test pattern application position, and a test pattern is formed by the inkjet head bar 5 in step SP16. Specifically, the ink jet head bar 5 is moved in the X direction, and the ejection operation is performed from all the ink jet nozzles 52 for each row of the ink jet heads 51 to eject and apply the coloring material. Form.

  If it is determined in step SP14 that it is not the first application of the outward path, or if the process of step SP16 is performed, whether or not a predetermined number of times of application for applying the entire application region has been performed in step SP17. Determine.

If it is determined in step SP17 that the number of times of application has not reached the predetermined number, in step SP18, the application gantry 4 is stopped, the inkjet head bar 5 is moved in the Y direction, and the determination in step SP7 is performed again.
The movement distance in the Y direction is determined by the effective application width of the ink jet head 51 according to the specifications of the ink jet head bar 5, and the application is completed without any gap by performing at least one reciprocating scan over the entire width of the application region.

  If it is determined in step SP17 that the predetermined number of times of application has been performed, the application process is terminated in step SP19, and in step SP20, all obtained in the “TP imaging flow” described in FIG. From the image of the landing mark of the coloring material discharged from the inkjet nozzle 52, it is determined whether or not the number of ejection failures of the inkjet nozzle 52 exceeds the number allowed in the range of the target pixel unit in the application region.

  As a result of the determination, if the occurrence of ejection failure of the inkjet head 51 exceeding the allowable range is confirmed, the process proceeds to the cleaning flow. If within the allowable range, the suction of the glass substrate 2 by the suction table 3 is performed in step SP21. The glass substrate 2 is unloaded by an unillustrated unloading robot or the like, and the series of processes is terminated as it is.

  On the other hand, if it is determined that the return path is determined in step 7, the application end process in step SP19 is performed through the “TP imaging flow” described in FIG. 9 in parallel with the return path movement of the application gantry 4 in step SP9. Move on.

  In the above-described example, the embodiment in which the application gantry 4 is moved in the X direction with respect to the suction table 3 has been described. However, the application gantry 4 may be fixed and the suction table 3 may be moved. It is.

In the above embodiment, the inkjet nozzle 52 to be ejected is selected and the number of ejections is controlled so that the total coating amount for the pixels on the color filter is made close to the necessary coating amount. No change is made to the amount per discharge discharged from the head.
However, by repeatedly performing the ejection operation of the inkjet nozzles 52 during the coating operation, the ejection amount from each inkjet nozzle 52 changes slightly, and the number of maintenance increases between coating processes in units of glass substrates. Inevitable.
If the frequency of maintenance can be suppressed by correcting the discharge amount of the ink jet nozzle 52 corresponding to the slight change in the discharge amount from the ink jet nozzle 52, it can be expected that productivity is improved.
Therefore, a nozzle control means (not shown) for changing the amount per discharge discharged from the ink jet nozzle 52 in the ink jet head 51 is discharged from the ink jet nozzle 52 in the ink jet head 51 to the coating device. It is preferable to further include upper control means (not shown) for controlling the control means of the ink jet nozzle 52 so that the total amount per discharge is close to a predetermined amount for each ink jet head 51.

  For example, the nozzle control means changes the discharge amount per discharge by changing the drive voltage applied to the inkjet nozzle 52.

  The upper control means receives, for example, discharge amount non-uniformity data obtained by the scan camera 9 as an input, and the total discharge amount per discharge of each ink jet nozzle 52 in the ink jet head 51 (inkjet head 51 The operation command to the control means of each inkjet nozzle 52 is performed so that the discharge amount per discharge) is close to the target discharge amount.

  In this case, the application amount of the coloring material of each pixel can be adjusted by controlling the discharge amount for each inkjet head 51. More specifically, even when a specific inkjet head 51 is affected by the viscosity of the ink and the discharge amount becomes low, an operation command for each nozzle control unit is set by the host control unit, and the nozzle control unit sets the inkjet nozzle. By changing the drive voltage applied to the nozzle 52, it is possible to suppress variations in the discharge amount with the other inkjet heads 51.

As described above, an application example for manufacturing a color filter used in a liquid crystal display device or the like has been described as a typical application example of a coating apparatus. However, this apparatus is a device for applying a coloring material or a coating material to other planar members. It is also possible to apply the above.

Perspective perspective view of an embodiment of a coating apparatus An example of the arrangement of the inkjet head of the inkjet head bar An example showing the nozzle arrangement of an inkjet head bar An example of selection when driving an inkjet nozzle Illustration of an example showing complementary application by reciprocating motion Timing chart of coating operation and coating pattern inspection process The figure of the state which applied six color filters and a test pattern on the substrate Partial enlarged view of the test pattern formation section Sample flow chart of test pattern inspection process Example of color filter manufacturing process flowchart

Explanation of symbols

2 Glass substrate 3 Suction table 5 Inkjet head bar 9 Scan camera 11 Image processing device 12 Memory 13 Control device 51 Inkjet head 52 Inkjet nozzle

Claims (4)

A coating apparatus that sprays and coats a coating material as a small amount of droplets by a discharge nozzle on a coating object using a coating head having a plurality of discharge nozzles,
In the process in which the coating head moves relative to the coating object, supplies a coating material to the coating object, and coats a region of an effective width or more of the coating head.
Intermittent application in which a part of the pixels in the application area of one application by the application head is thinned out, and complementing the intermittent application part and the remaining application area by scanning the application head at least once or more,
A coating apparatus for uniformly coating a coating material over the entire required coating area of the coating object 2. The application according to claim 1, wherein the width of the intermittent application region is at least the width of the application region of the discharge nozzle having a low relative discharge amount located at both ends of all the discharge nozzles of the application head, and / or at least 3 pixels or more. apparatus An application method in which an application material having a plurality of discharge nozzles is used to spray and apply an application material as a small amount of droplets to the application object using the discharge nozzles,
In the process in which the coating head moves relative to the coating object, supplies a coating material to the coating object, and coats a region of an effective width or more of the coating head.
Intermittent application in which a part of the pixels in the application area of one application by the application head is thinned out, and complementing the intermittent application part and the remaining application area by scanning the application head at least once or more,
A coating method characterized by uniformly coating a coating material over the entire necessary coating area of the coating object 4. The application according to claim 3, wherein the width of the intermittent application region is at least the width of the application region of the discharge nozzle having a low relative discharge amount located at both ends of all the discharge nozzles of the application head, and / or at least 3 pixels or more. Method

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